Non-linear behavior of ground-supported circular reinforced concrete tanks

2021 ◽  
Author(s):  
Maryam Rafieeraad ◽  
M. Reza Kianoush ◽  
Mehdi Moslemi
Keyword(s):  
Seismic Behavior ◽  
Current Practice ◽  
Time History ◽  
Response Modification Factor ◽  
R Factor ◽  
Linear Behavior ◽  
History Analysis ◽  
Earthquake Frequency ◽  
Modification Factor ◽  
Nonlinear Static

This study aims to investigate the effect of various parameters on the seismic behavior of concrete tanks. A finite element method using pushover and time-history analysis is developed to investigate the seismic behavior of circular ground-supported tanks. The response modification factor (R) is evaluated based on nonlinear static and time-history analyses. R factor is one of the key parameters in seismic design. In liquid containing structures, R-Factor in current codes and standards are based on empirical values. Therefore, a justifiable guideline to accurately determine these values is yet to be developed. This study shows that the effect of tank size, material non-linearity, base condition, and earthquake frequency content is significant. Also, fixed based and shallow tanks have higher R values compared to hinged based and tall tanks, respectively. Based on the results of this study, it is found that the value of R specified in current practice is not appropriate.

scholarly journals Nonlinear seismic response of ground supported cylindrical reinforced concrete tanks

2021 ◽  
Author(s):  
Maryam Rafieeraad
Keyword(s):  
Seismic Behavior ◽  
Time History ◽  
Material Nonlinearity ◽  
Ground Acceleration ◽  
Response Modification Factor ◽  
R Factor ◽  
Earthquake Frequency ◽  
Modification Factor ◽  
Vertical Ground ◽  
Strength And Ductility

Seismic behavior of Liquid Containing Structures has been studied for decades. Being able to have these structures functioning during and after an earthquake is imperative for well-being of a society hence importance of their design. Response Modification Factor known as “R factor” is one of the key parameters in seismic design. However, in case of LCS’s, a justifiable guideline to determine the R factor is yet to be developed and current codes have utilized empirical values in design of these structures. The design intend for LCS’s is to meet the serviceability limits as opposed to life safety and collapse prevention which is the case of design of buildings. This study aims to investigate the effect of various parameters such as material nonlinearity, tank dimensions, base condition, concrete compressive strength, characteristics of seismic excitation records on the seismic behavior of concrete tanks. In this study, a finite element method is developed to investigate the seismic behavior of circular ground supported reinforced concrete tanks. First, the accuracy of current practice is investigated by employing the analytical and numerical methods, experimental studies. Finite element technique and pushover analysis are utilized to set up the pushover curve and achieve over-strength and ductility factors. The response modification factor (R) is then evaluated based on the nonlinear static analysis. Second, using the nonlinear dynamic analysis (time-history), the seismic behavioral aspects of full liquid tanks are studied taking into account the material nonlinearity, wall flexibility, effect of impulsive component, fluid-surface interaction and vertical ground acceleration. Thereafter, a parametric study is conducted to study the influence of tank dimensions, base fixity conditions and earthquake frequency content on the response modification factor. This study shows the over-strength and ductility factor of RC ground-supported tanks are significantly influence by tank size, height, height/diameter ratio and fundamental period. Also, fixed based tanks and shallow tanks have higher R values compared to hinged based and tall tanks respectively. The time history results show that the effect of material nonlinearity, vertical ground acceleration, base condition and earthquake frequency content on the dynamic behavior of liquid ground supported tanks is significant.

scholarly journals Nonlinear seismic response of ground supported cylindrical reinforced concrete tanks

2021 ◽  
Author(s):  
Maryam Rafieeraad
Keyword(s):  
Seismic Behavior ◽  
Time History ◽  
Material Nonlinearity ◽  
Ground Acceleration ◽  
Response Modification Factor ◽  
R Factor ◽  
Earthquake Frequency ◽  
Modification Factor ◽  
Vertical Ground ◽  
Strength And Ductility

Seismic behavior of Liquid Containing Structures has been studied for decades. Being able to have these structures functioning during and after an earthquake is imperative for well-being of a society hence importance of their design. Response Modification Factor known as “R factor” is one of the key parameters in seismic design. However, in case of LCS’s, a justifiable guideline to determine the R factor is yet to be developed and current codes have utilized empirical values in design of these structures. The design intend for LCS’s is to meet the serviceability limits as opposed to life safety and collapse prevention which is the case of design of buildings. This study aims to investigate the effect of various parameters such as material nonlinearity, tank dimensions, base condition, concrete compressive strength, characteristics of seismic excitation records on the seismic behavior of concrete tanks. In this study, a finite element method is developed to investigate the seismic behavior of circular ground supported reinforced concrete tanks. First, the accuracy of current practice is investigated by employing the analytical and numerical methods, experimental studies. Finite element technique and pushover analysis are utilized to set up the pushover curve and achieve over-strength and ductility factors. The response modification factor (R) is then evaluated based on the nonlinear static analysis. Second, using the nonlinear dynamic analysis (time-history), the seismic behavioral aspects of full liquid tanks are studied taking into account the material nonlinearity, wall flexibility, effect of impulsive component, fluid-surface interaction and vertical ground acceleration. Thereafter, a parametric study is conducted to study the influence of tank dimensions, base fixity conditions and earthquake frequency content on the response modification factor. This study shows the over-strength and ductility factor of RC ground-supported tanks are significantly influence by tank size, height, height/diameter ratio and fundamental period. Also, fixed based tanks and shallow tanks have higher R values compared to hinged based and tall tanks respectively. The time history results show that the effect of material nonlinearity, vertical ground acceleration, base condition and earthquake frequency content on the dynamic behavior of liquid ground supported tanks is significant.

Response modification factors for steel buckling restrained braced frames designed as per the 2010 National Building Code of Canada

2016 ◽  
Vol 43 (8) ◽  
pp. 702-715 ◽  
Author(s):  
Moniruzzaman Moni ◽  
Saber Moradi ◽  
M. Shahria Alam
Keyword(s):  
Time History ◽  
Building Code ◽  
Braced Frames ◽  
Response Modification Factor ◽  
Building Frames ◽  
Modification Factor ◽  
Design Values ◽  
Nonlinear Static ◽  
Buckling Restrained Braced Frames ◽  
Dynamic Time

This paper evaluates the overstrength, ductility, and response modification factors for low to mid-rise buckling restrained braced frames (BRBFs) designed as per the 2010 National Building Code of Canada. In addition to nonlinear static pushover analyses, dynamic time history analyses are performed to assess the seismic performance of four-, six-, and eight-story BRBFs. Different bracing configurations, including chevron (inverted-V) and split-X braces, are considered for the building frames with varied frame span lengths of 6 m and 8 m. The results confirm that the prescribed design values for overstrength and ductility factors provide reasonable estimations of the lower bound for these factors. The response modification factor obtained in this study ranged from 4.8 to 6 for different frames. The results also indicate that the response modification factor decreases with the increase of story height and span length. Moreover, bracing configurations may slightly affect the response modification factor for BRBFs.

scholarly journals Seismic Performance Analysis of a Connected Multitower Structure with FPS and Viscous Damper

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Xiaohan Wu ◽  
Jun Wang ◽  
Jiangyong Zhou
Keyword(s):  
Seismic Behavior ◽  
Passive Control ◽  
Time History ◽  
Tuned Mass Damper ◽  
Seismic Excitations ◽  
History Analysis ◽  
Mass Damper ◽  
Tower Structure ◽  
Design Requirements ◽  
Friction Pendulum

A high four-tower structure is interconnected with a long sky corridor bridge on the top floor. To reduce the earthquake responses and member forces of the towers and sky corridor bridge, a passive control strategy with a friction pendulum tuned mass damper (FPTMD) was adopted. The sky corridor bridge was as the mass of FPTMD. The connection between the towers and the sky corridor bridge was designed as flexible links, where friction pendulum bearings (FPBs) and viscous dampers were installed. Elastoplastic time-history analysis was conducted by using Perform-3D model to look into its seismic behavior under intensive seismic excitation. The optimal design of the FPTMD with varying friction coefficients and radius of friction pendulum bearing (FPB) under seismic excitations was carried out, and the seismic behavior of the structure was also investigated at the same time.Results show that, for this four-tower connected structure, the friction pendulum tuned mass damper (FPTMD) has very well effect on seismic reduction. The structure can meet the seismic resistance design requirements.

scholarly journals Evaluation of p-delta effect in structural seismic response

2018 ◽  
Vol 162 ◽  
pp. 04019 ◽  
Author(s):  
Sardasht Sardar ◽  
Ako Hama
Keyword(s):  
Seismic Response ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Steel Structure ◽  
Nonlinear Static Analysis ◽  
Structural Behavior ◽  
Finite Element Software ◽  
History Analysis ◽  
Nonlinear Static

Numerous recent studies have assessed the effect of P-Delta on the structures. This paper investigates the effect of P-Delta in seismic response of structures with different heights. For indicating the effect of P-Delta, nonlinear static analysis (pushover analysis) and nonlinear dynamic analysis (Time history analysis) were conducted by using finite element software. The results showing that the P-Delta has a significant impact on the structural behavior mainly on the peak amplitude of building when the height of the structures increased. In addition, comparison has been made between concrete and steel structure.

Seismic Behavior of Shifang Telecom Building under Conventional Earthquakes

2010 ◽  
Vol 163-167 ◽  
pp. 4227-4231
Author(s):  
Xiao Hu ◽  
Yong Tao Gao
Keyword(s):  
Numerical Simulation ◽  
Spectrum Analysis ◽  
Seismic Behavior ◽  
Time History ◽  
Internal Force ◽  
Seismic Effect ◽  
Time History Analysis ◽  
History Analysis ◽  
Seismic Impact

To study the seismic behavior under conventional earthquakes, according to a case of Shifang Telecom Building (STB) under 5.12 earthquake, this paper makes the computation of internal force and deformation of structure; then compares the seismic behavior of two different models with spectrum analysis and time-history analysis. The conclusion shows that STB can approximately meet requirements for fortification against seismic impact under conventional earthquakes; the steel tower on top can amplify the seismic effect indeed and the weakness of numerical simulation tallies with the reality.

scholarly journals Seismic Response Modification Factorof Reinforced Concrete Frames Basedon Pushover Analysis

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Amira Elyamany Mohamed ◽  
Walid A Attia ◽  
Wael M. El-Degwy
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Fundamental Period ◽  
Concrete Frames ◽  
Reinforced Concrete Frames ◽  
Response Modification Factor ◽  
R Factor ◽  
Modification Factor ◽  
The Given

Response modification factor is an essential factor in seismic analysis to provide economic design of reinforced concrete structures. Base shear force is divided by the response modification factor to consider the ability of the structure to dissipate energy through plastic hinges. The current study investigates the effects of changing some parameters on response modification factor (R-factor). Four groups of reinforced concrete frames were studied with different number of bays, number of stories, load pattern, and fundamental period of vibration. All reinforced concrete frames were analyzed using SAP 2000 then the straining actions results were used at specific excel sheets which are developed to design reinforced concrete members according to the Egyptian code of practice ECP-203 and ECP-201. Frames were analyzed by nonlinear static analysis (pushover analysis) using SAP2000. A sum of thirty two systems of frames was analyzed. According to the results, every frame has its unique value of R-factor. Accordingly, many parameters should be mentioned and considered at code to simulate the actual value of R-factor for each frame. Response modification factor is affected by many factors like stiffness, fundamental period of vibration, number of bays, frame height, geometry of the structure, etc. The given values of R-factor at ECP-201 can be considered conservative; as the accurate values of R-factor is higher than the given values.

Study on Seismic Behavior of Steel & Concrete Hybrid Structure

2011 ◽  
Vol 90-93 ◽  
pp. 1406-1411
Author(s):  
Qiang Song ◽  
Yong Zhang ◽  
Yong Xu
Keyword(s):  
Seismic Behavior ◽  
Response Spectrum ◽  
Time History ◽  
Hybrid Structure ◽  
Calculation Model ◽  
Response Spectrum Analysis ◽  
Core Tube ◽  
The Core ◽  
History Analysis ◽  
Simplified Calculation

Seismic behavior of the steel & concrete hybrid structure is studied by Sap2000, including modal analysis, response spectrum analysis and time-history analysis. Also, a simplified calculation model of the steel & concrete hybrid structure is established, and some formulae have been derived from this model, such as the natural frequency, top displacement, shear of both the core tube and the steel frame, on the basis of finite element method of bar system. Those formulae can be used to explain and approximately count the seismic response of steel & concrete hybrid structure.

scholarly journals Seismic Response Analysis of Prestressed Concrete Rocking Frame

2021 ◽  
Vol 11 (2) ◽  
pp. 585
Author(s):  
Zixiang Zhao ◽  
Xiaozu Su
Keyword(s):  
Theoretical Model ◽  
Seismic Response ◽  
Prestressed Concrete ◽  
Seismic Behavior ◽  
Time History ◽  
Equation Of Motion ◽  
Parameter Analysis ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
History Analysis

In order to investigate the seismic performance of prestressed concrete rocking frame (PCRF), a theoretical model based on rigid body is established for a one-story single-span PCRF. The PCRF studied in this paper has the connecting interfaces set at the column feet and at the inner faces of the beam–column joints, allowing the columns to be uplifted with the accompanying separation of the beam–column interface and rotation of the beam and column around the interface. The tendons are arranged along the centerline of the beam and columns. The connections between the beam and columns and the anchoring of columns are accomplished by prestressing the tendons. The theoretical model consists of a rigid beam, rigid columns and elastic tendons. The governing motion equation of the PCRF is derived based on the model and a numerical solution of the equation of motion is obtained. The energy dissipation of the PCRF is analyzed and the calculation method for the coefficient of restitution is derived. Time history analysis and parameter analysis of seismic response of the PCRF are conducted and the results show that the PCRF has promising seismic behavior.

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